From: Misclassification and characterization of exposure to humidifier disinfectants using a questionnaire
 |  | Clinical class | Total | p-value | |||
---|---|---|---|---|---|---|---|
Class 1 | Class 2 | Class 3 | Class 4 | ||||
Indoor concentration | Rating 1 | 2406 | 172 | 134 | 157 | 2869 | 0.04 |
Rating 2 | 165 | 12 | 10 | 19 | 206 | ||
Rating 3 | 137 | 16 | 7 | 13 | 173 | ||
Rating 4 | 169 | 9 | 8 | 22 | 208 | ||
Cumulative exposure time | Rating 1 | 2339 | 186 | 144 | 200 | 2869 | < 0.01 |
Rating 2 | 188 | 7 | 6 | 5 | 206 | ||
Rating 3 | 159 | 6 | 5 | 3 | 173 | ||
Rating 4 | 191 | 10 | 4 | 3 | 208 | ||
Exposure level | Rating 1 | 2357 | 181 | 143 | 188 | 2869 | < 0.01 |
Rating 2 | 166 | 15 | 12 | 13 | 206 | ||
Rating 3 | 162 | 2 | 0 | 9 | 173 | ||
Rating 4 | 192 | 11 | 4 | 1 | 208 | ||
 | Total | 2877 | 209 | 159 | 211 | 3456 |  |